SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '657a4c2499352309bd8d0c474f0b6d6ce51fb259115b1dfd7632c0fc07ef08b1' 
  AND token = '6ATXZdOK8FTtU+7kzijLnCbE6uuxcwYXlO0C5MYGxZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}